Initial Interop Updates (#492)

* Add interop chain spec and rename chain_id

* Add ability to connect to raw libp2p nodes

* Adds Identify protocol, clean up RPC protocol name handling

* Update to latest libp2p, gossipsub improvements

* Updates to latest interop branch.

- Shifts decoding of objects into message handler.
- Updates to latest interop gossipsub.
- Adds interop spec constant.

* Configuration updates allow for verbosity CLI flag and spec constants

* Update submodules to master

* Correct minimal chainspec modifications

* Duplication of validator polls are no longer fatal

* Apply PR suggestions

beacon_node/rpc/src/lib.rs

@@ -25,7 +25,7 @@ use tokio::sync::mpsc;
 pub fn start_server<T: BeaconChainTypes + Clone + 'static>(
     config: &RPCConfig,
     executor: &TaskExecutor,
-    network_chan: mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
+    network_chan: mpsc::UnboundedSender<NetworkMessage>,
     beacon_chain: Arc<BeaconChain<T>>,
     log: &slog::Logger,
 ) -> exit_future::Signal {